Association of Serum Uric Acid Level With Blood Pressure Variability in Newly Diagnosed Essential Hypertension

Efficacy of angiotensin receptor blockers for nocturnal blood pressure reduction: a systematic review and meta-analysis

BACKGROUND

Nocturnal blood pressure (BP) is correlated with an increased risk of cardiovascular events and is an important predictor of cardiovascular death in hypertensive patients.

OBJECTIVE

Nocturnal BP control is of great importance for cardiovascular risk reduction. This systematic review and meta-analysis aimed to explore the efficacy of angiotensin receptor blockers (ARBs) for nocturnal BP reduction in patients with mild to moderate hypertension.

METHODS

PICOS design structure was used to formulate the data extraction. All statistical calculations and analyses were performed with R.

RESULTS

Seventy-seven studies with 13,314 participants were included. The overall analysis indicated that nocturnal BP drop varied considerably among different ARBs. Allisartan (13.04 [95% CI (-18.41, -7.68)] mmHg), olmesartan (11.67 [95% CI (-14.12, -9.21)] mmHg), telmisartan (11.11 [95% CI (-12.12, -10.11)] mmHg) were associated with greater reduction in nocturnal systolic BP. In the aspect of the nocturnal-diurnal BP drop ratio, only allisartan was greater than 1. While, the variation tendency of last 4-6 h ambulatory BP was basically consistent with nocturnal BP. Additionally, allisartan showed improvement effect in the proportion of patients with dipping BP pattern.

CONCLUSIONS

This study demonstrates that for patients with mild to moderate hypertension, allisartan, olmesartan and telmisartan have more advantages in nocturnal BP reduction among the ARBs, while allisartan can reduce nighttime BP more than daytime BP and improve the dipping pattern.

Allopurinol and blood pressure variability following ischemic stroke and transient ischemic attack: a secondary analysis of XILO-FIST

Blood Pressure Variability (BPV) is associated with cardiovascular risk and serum uric acid level. We investigated whether BPV was lowered by allopurinol and whether it was related to neuroimaging markers of cerebral small vessel disease (CSVD) and cognition. We used data from a randomised, double-blind, placebo-controlled trial of two years allopurinol treatment after recent ischemic stroke or transient ischemic attack. Visit-to-visit BPV was assessed using brachial blood pressure (BP) recordings. Short-term BPV was assessed using ambulatory BP monitoring (ABPM) performed at 4 weeks and 2 years. Brain MRI was performed at baseline and 2 years. BPV measures were compared between the allopurinol and placebo groups, and with CSVD and cognition. 409 participants (205 allopurinol; 204 placebo) were included in the visit-to-visit BPV analyses. There were no significant differences found between placebo and allopurinol groups for any measure of visit-to-visit BPV. 196 participants were included in analyses of short-term BPV at week 4. Two measures were reduced by allopurinol: the standard deviation (SD) of systolic BP (by 1.30 mmHg (95% confidence interval (CI) 0.18-2.42, p = 0.023)); and the average real variability (ARV) of systolic BP (by 1.31 mmHg (95% CI 0.31-2.32, p = 0.011)). There were no differences in other measures at week 4 or in any measure at 2 years, and BPV was not associated with CSVD or cognition. Allopurinol treatment did not affect visit-to-visit BPV in people with recent ischemic stroke or TIA. Two BPV measures were reduced at week 4 by allopurinol but not at 2 years.

Systemic Endothelial Function, Plasma Xanthine Oxidoreductase Activity, and Blood Pressure Variability in Patients with Stable Coronary Artery Disease

Background and Objectives: Although previous studies showed that an activity of xanthine oxidoreductase (XOR), a rate-limiting enzyme in purine metabolism, beyond the serum uric acid level, was associated with the development of coronary artery disease (CAD), the underlying mechanisms are unclear. Because endothelial dysfunction and a greater blood pressure (BP) variability may play a role, we investigated the relations among the endothelial function, XOR, and BP variability. Materials and Methods: This was a post-hoc study using pooled data of patients with a stable CAD from two prospective investigations, in which the systemic endothelial function was assessed with the reactive hyperemia index (RHI) and the XOR activity was measured. The BP variability was evaluated using BP measurements during the three- and four-day hospitalization. Results: A total of 106 patients with a stable CAD undergoing a percutaneous coronary intervention were included. Of the 106 patients, 46 (43.4%) had a systemic endothelial dysfunction (RHI < 1.67). The multivariable analysis identified a higher body mass index (BMI), female gender, and diabetes as factors associated with an endothelial dysfunction. A higher BMI was also related to an elevated XOR activity, in addition to current smoking. No significant correlation was observed between the RHI and XOR activity. Similarly, the in-hospital BP variability was associated with neither the endothelial function nor XOR. Conclusions: Among patients with a stable CAD, several factors were identified as being associated with a systemic endothelial dysfunction or an elevated XOR activity. However, no direct relations between the endothelial function, XOR, and BP variability were found.

Impact of febuxostat on visit-to-visit blood pressure variability: insights from the randomised PRIZE Study

Objectives

Although uric acid lowering therapies, including xanthine oxidase (XO) inhibition, may reduce the absolute level of blood pressure (BP), the effect of XO inhibition on BP variability is largely unknown. The aim of the present analysis was to evaluate the impact of febuxostat, an XO inhibitor, on BP variability in a randomised trial setting.

Methods

This was a subanalysis of the PRIZE Study, a randomised trial to evaluate the potential effect of febuxostat on carotid intima–media thickness progression. Patients with hyperuricemia and carotid plaques were randomly assigned to the febuxostat or control group. During a 24-month period, office BP and pulse rate (PR) were measured ≥3 times. BP and PR variabilities were assessed with SD and coefficient of variation (CV). The effect of febuxostat on BP and PR variabilities was adjusted with age, sex and baseline BP or PR, expressed with 95% CIs.

Results

A total of 472 patients were included into the present subanalysis. During the 24-month follow-up period, the febuxostat group had a significantly lower adjusted mean systolic BP (128.4 (126.8–130.0) vs 130.7 (129.1–132.2) mm Hg, p=0.04) and CV of systolic BP (7.4 (6.7–8.0) vs 8.2 (7.6–8.8), p=0.04) than the control group. Adjusted SD of PR was also lower in the febuxostat group than their counterpart (5.95 (4.93–6.97) vs 7.33 (6.32–8.33), p=0.04).

Conclusion

XO inhibition with febuxostat was associated with reduced visit-to-visit BP variability as well as reduced PR variability in patients with hyperuricemia and carotid plaques.

Trial registration numbers

University Hospital Medical Information Network Clinical Trial Registry (UMIN000012911 and UMIN000041322).

The assessment of hypertension in kidney transplant patients: time to change our approach?

Kidney transplantation (KT) is an increasingly utilized treatment for end-stage kidney disease. Hypertension either as a cause of kidney disease or as a complication of chronic kidney disease is the most frequently encountered comorbidity of KT patients. Hence, the management of hypertension in KT patients is crucial to prolong patient and graft survival. Ambulatory blood pressure monitoring (ABPM) appeared as a promising technique that has superiority over office and home blood pressure (BP) monitoring to correctly diagnose and manage hypertension. A recent meta-analysis by Pisano et al. including 42 studies with 4115 participants provided strong data for the comparison of ABPM with office BP monitoring in KT patients. In addition to the current literature knowledge, the findings of Pisano et al. filled the long-awaited evidence gap to suggest ABPM as a first-line BP monitoring technique for KT patients. Despite its disadvantages, such as patient discomfort, cost–effectiveness and limited availability, ABPM has crucial advantages in the management of hypertension including the detection of abnormal circadian BP patterns, the assessment of effects of physical activity and short-term variability of BP, and the exclusion of masked and white-coat hypertension.

Elevated serum uric acid is associated with incident hypertension in the health according to various contemporary blood pressure guidelines

BACKGROUND AND AIMS

Elevated serum uric acid (SUA) is associated with hypertension according to its traditional definition. We investigated the association between SUA and incident hypertension according to the European Society of Cardiology (ESC) and American Society of Cardiology (ACC) guidelines.

METHODS AND RESULTS

In this retrospective cohort study, we enrolled 10,537 healthy individuals ≥30 years old who underwent a routine annual health examination with office blood pressure recorded at our hospital in 2016; of the participants, 7349 repeated the exam in 2017. According to the ESC and ACC guidelines, hypertension was defined as office BP ≥ 140/90 mmHg or ≥130/80 mmHg. Hyperuricemia (HUA) was defined as SUA ≥7 mg/dL in men and ≥6 mg/dL in women. The hypertension incidence was 5.8% among 6378 individuals in the ESC cohort and 19% among 4330 individuals in the ACC cohort. Incident hypertension was significantly more common in the hyperuricemic group than in the normouricemic group (ESC: 8.6% vs. 4.7%, P < 0.001; ACC: 25.5% vs. 16.9%, P < 0.001). In the fully adjusted multivariate logistic regression analyses, each increase in SUA was associated with an increase in incident hypertension risk (ESC: adjusted OR: 1.167, 95% CI: 1.061-1.284, P = 0.001; ACC: adjusted OR: 1.125, 95% CI: 1.044-1.213, P = 0.002). The association can be explained by a significant correlation of baseline SUA with the BP in the following year (r = 0.24, P < 0.001 for baseline SUA and SBP in the following year; r = 0.239, P < 0.001 for baseline SUA and DBP in the following year).

CONCLUSION

Elevated SUA was associated with incident hypertension in healthy individuals according to various contemporary BP guidelines (ClinicalTrials.gov: NCT03473951).

CLINICAL TRIALS

ClinicalTrials.gov with the identification number of NCT03473951.

Cardiovascular benefits of sodium-glucose cotransporter 2 inhibitors in diabetic and nondiabetic patients

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) were developed as antidiabetic agents, but accumulating evidence has shown their beneficial effects on the cardiovascular system. Analyses of the EMPA-REG OUTCOME trial (Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients) suggested that these benefits are independent of glycemic control. Several large-scale outcome trials of SGLT2i also showed cardiovascular benefits in nondiabetic patients, strengthening this perspective. Extensive animal and clinical studies have likewise shown that mechanisms other than the antihyperglycemic effect underlie the cardiovascular benefits. Recent clinical guidelines recommend the use of SGLT2i in patients with type 2 diabetes mellitus and cardiovascular diseases because of the proven cardiovascular protective effects. Since the cardiovascular benefits are independent of glycemic control, the therapeutic spectrum of SGLT2i will likely be extended to nondiabetic patients.

Uric Acid Variability and All-Cause Mortality: A Prospective Cohort Study in Northern China

OBJECTIVES

Uric acid(UA) is related with cardiovascular disease, but the association of UA variability with all-cause mortality is rarely known. This study aimed to investigate the relationship between UA variability and all-cause mortality in Kailuan cohort study in northern China.

DESIGN

Cohort study.

SETTING

Kailuan community hospitals in Tangshan, Hebei province, Northern China.

PARTICIPANTS

A total of 55717 participants from Kailuan Study were enrolled, and our study followed up biennially from 2006 to 2010.

MEASUREMENTS

Clinical records of the participants enrolled were analyzed. UA variation independent of mean (UAVIM) values were calculated and all the participants were quartile grouped into four groups as: Q1(UAVIM<0.68), Q2(0.68≤UAVIM<1.10), Q3(1.10≤UAVIM<1.67) and Q4(UAVIM≥1.67). The endpoint event was all-cause death. Cox regression model was performed to evaluate the hazard ratios(HRs) of all-cause mortality based on UAVIM groups.

RESULTS

During a median follow-up of 6.83 years, 2926 deaths occurred. The accumulated mortality rates were 4.6%, 4.8%, 5.4% and 6.1% in group Q1, Q2, Q3 and Q4 respectively. When adjusted potential confounders, the highest risk for all-cause mortality was in group Q4 and the adjusted HRs and 95% confidence intervals(CIs) of group Q2-Q4 for all-cause death were 1.044(0.937, 1.164), 1.182(1.064, 1.314) and 1.353(1.220, 1.501) compared with group Q1, respectively. Further analysis showed that the risk for all-cause death increased as UAVIM value increased. Sensitive analysis still showed the similar results when excluding participants with hyperuricemia or severe chronic kidney diseases. Sub-group analysis by age, gender, BMI or hypertension history also indicated analogous results.

CONCLUSION

Elevated UAVIM was related with increased all-cause mortality and UAVIM was an independent risk factor for all-cause mortality in the community cohort study.

Impact of Uric Acid on Hypertension Occurrence and Target Organ Damage: Insights From the STANISLAS Cohort With a 20-Year Follow-up

BACKGROUND

Recent studies have shown that hyperuricemia may be associated with incident hypertension (HTN). We examined whether serum uric acid (SUA) is a predictor of HTN and target organ damage (TOD) 20 years later in initially healthy middle-aged individuals.

METHODS

Participants from the Suivi Temporaire Annuel Non-Invasif de la Santé des Lorrains Assurés Sociaux (STANISLAS) a single-center familial longitudinal cohort study (961 initially healthy adults and 570 children) underwent clinical and laboratory measurements at baseline and after approximately 20 years. Blood pressure (BP: using ambulatory BP measurements), urine albumin-to-creatinine ratio, estimated glomerular filtration rate (eGFR), left ventricular hypertrophy (LVH), diastolic dysfunction, and carotid-femoral pulse wave velocity (PWV) were measured at the end of follow-up.

RESULTS

In the parent population, higher baseline or last SUA levels and higher change in SUA (ΔUA) were significantly associated with an increased risk of HTN development, even after adjusting for known HTN risk factors (all P < 0.01). Higher baseline SUA was marginally associated with an increased risk of having high carotid-femoral PWV (P = 0.05). The association of SUA with BP increase was body mass index dependent (the increase in BP being greater in leaner subjects; interactionp < 0.05), and the association of SUA with eGFR decline was age dependent (the decline in eGFR being greater in older subjects; interactionp < 0.05). There was no significant association between SUA and diastolic dysfunction or LVH. In the whole population (i.e. including children), a significant association between SUA at baseline and the risk of HTN and higher carotid-femoral PWV was also found (both P < 0.02).

CONCLUSIONS

Increased SUA is associated with the development of HTN and vascular/renal TOD in initially healthy midlife subjects.

The association of urinary uric acid excretion with ambulatory blood pressure values in patients with chronic kidney disease

BACKGROUND

To analyze the association between hypertension and urinary uric acid excretion in patients with chronic kidney disease (CKD).

METHODS

We screened 87 patients who had been admitted at the Dept of Nephrology, Huadong hospital between April 2017 to April 2019 who had completed 24-h ambulatory blood pressure monitoring and retained 24-h urine biochemical test specimens, thirty adult patients (age ≤ 65 years) with CKD 1-2 stages were recruited in the study. Pearson's correlation analysis and multiple linear regression analysis were used to study the correlation of urinary uric acid excretion with ambulatory blood pressure values and the association of morning mean diastolic pressure (mMDP), night mean diastolic pressure (nMDP) and CV of dMSP (coefficient of variation of day mean systolic pressure) with fractional excretion of uric acid (FEua) and uric acid clearance rate (Cur). Independent T test was used to compare the differences of blood pressure values in FEua1 (FEua< 6.0%) and FEua2 (FEua≥6.0%) or Cur1 (Cur < 6.2 ml/min/1.73 m2) and Cur2 (Cur ≥ 6.2 ml/min/1.73m2) groups according to the median of FEua or Cur, respectively.

RESULTS

After adjusting for confounding factors, multiple linear regression analysis showed that FEua was positively associated with the mMDP and nMDP, Cur was positively associated with CV of dMSP. Levels of mMDP and nMDP in FEua1 group was lower than that in FEua2 group (both P < 0.05), level of CV of dMSP in Cur2 group were higher than that in Cur1 group (P < 0.01).

CONCLUSIONS

We demonstrated that there is a positive correlation of FEua with morning and night mean diastolic pressure separately and Cur is positively related to CV of dMSP in CKD population. Monitoring the trend of urinary uric acid, may have a role in the early detection for hypertension or relative risks in the population of CKD.

Hyperuricemia and Cardiovascular Disease

Purine metabolism in the circulatory system yields uric acid as its final oxidation product, which is believed to be linked to the development of gout and kidney stones. Hyperuricemia is closely correlated with cardiovascular disease, metabolic syndrome, and chronic kidney disease, as attested by the epidemiological and empirical research. In this review, we summarize the recent knowledge about hyperuricemia, with a special focus on its physiology, epidemiology, and correlation with cardiovascular disease. This review also discusses the possible positive effects of treatment to reduce urate levels in patients with cardiovascular disease and hyperuricemia, which may lead to an improved clinical treatment plan.

Hyperuricemia and Hypertension: Links and Risks

Hyperuricemia has long been recognized to be associated with increased cardiovascular risk, including risk of developing hypertension. Epidemiological findings suggest that the link with hypertension is stronger in children and adolescents. Uric acid acts as a strong antioxidant compound in the extracellular environment but has pro-inflammatory effects within the intracellular setting. A chronic phase of microvascular injury is known to occur after prolonged periods of hyperuricemia. This is proposed to contribute to afferent arteriolopathy and elevation of blood pressure that may become unresponsive to uric acid-lowering therapies over time. Studies have struggled to infer direct causality of hyperuricemia due to a vast number of confounders including body mass index. The aim of this review is to present the available data and highlight the need for large scale prospective randomized controlled trials in this area. At present, there is limited evidence to support a role for uric acid-lowering therapies in helping mitigate the risk of hypertension.

Uric acid and the cardio-renal effects of SGLT2 inhibitors

Sodium/glucose co-transporter-2 (SGLT2) inhibitors, which lower blood glucose by increasing renal glucose elimination, have been shown to reduce the risk of adverse cardiovascular (CV) and renal events in type 2 diabetes. This has been ascribed, in part, to haemodynamic changes, body weight reduction and several possible effects on myocardial, endothelial and tubulo-glomerular functions, as well as to reduced glucotoxicity. This review evaluates evidence that an effect of SGLT2 inhibitors to lower uric acid may also contribute to reduced cardio-renal risk. Chronically elevated circulating uric acid concentrations are associated with increased risk of hypertension, CV disease and chronic kidney disease (CKD). The extent to which uric acid contributes to these conditions, either as a cause or an aggravating factor, remains unclear, but interventions that reduce urate production or increase urate excretion in hyperuricaemic patients have consistently improved cardio-renal prognoses. Uric acid concentrations are often elevated in type 2 diabetes, contributing to the "metabolic syndrome" of CV risk. Treating type 2 diabetes with an SGLT2 inhibitor increases uric acid excretion, reduces circulating uric acid and improves parameters of CV and renal function. This raises the possibility that the lowering of uric acid by SGLT2 inhibition may assist in reducing adverse CV events and slowing progression of CKD in type 2 diabetes. SGLT2 inhibition might also be useful in the treatment of gout and gouty arthritis, especially when co-existent with diabetes.

Relation of uric acid level to rapid kidney function decline and development of kidney disease: The Jackson Heart Study

Whether elevated uric acid (UA) is an independent risk factor for chronic kidney disease (CKD) is not well established. The authors evaluated the relationship of UA with rapid kidney function decline (RKFD) and incident CKD among 3702 African Americans (AAs) in the Jackson Heart Study with serum UA levels measured at baseline exam (2000-2004). RKFD was defined as ≥ 30% eGFR loss and incident CKD as development of eGFR < 60 mL/min/1.73 m2 with a ≥ 25% decline in eGFR between baseline and exam 3 (2009-2013). RKFD and CKD were found in 11.4% and 7.5% of the participants, respectively. In a fully adjusted model, the odds of RKFD (OR, 1.8; 95% CI, 1.25-2.49) and incident CKD (OR, 2.00; 95% CI, 1.31-3.06) were significantly higher among participants in the top UA quartile vs bottom quartile. In the JHS, elevated UA was significantly associated with RKFD and incident CKD.

Impact of in-hospital blood pressure variability on cardiovascular outcomes in patients with acute coronary syndrome

To evaluate the impact of blood pressure variability (BPV) on cardiovascular outcomes in patients with acute coronary syndrome, short-term BPV was estimated by using weighted standard deviation of 24-hour ambulatory blood pressure monitoring readings. The primary outcome was in-hospital major adverse cardiac events (MACE). Overall, 200 patients (mean age, 58.6 years; 27.5% women; 38% with diabetes mellitus; and 47% smokers) were divided into low and high BPV groups based on the median value (9.45). Patients in the high BPV group were more likely to have in-hospital MACE compared with patients with low BPV (47% vs 27%, P = .003). Multivariate binary logistic regression analysis of incidence of MACE showed that BPV (odds ratio, 2.4; confidence interval, 1.2-4.5 [P = .008]) and presence of type II diabetes mellitus (odds ratio, 2.6; confidence interval, 1.2-5.3 [P = .008]) were the only independent predictors of in-hospital MACE derived mainly by hypertensive emergencies. BPV could be an important risk factor for in-hospital MACE in patients with acute coronary syndrome.

Effects of serum uric acid on blood-pressure lowering treatment

If hyperuricemia is an independent risk factor in blood-pressure control, urate-lowering therapy should be used to reduce cardiovascular risk. It may also act as a prognostic marker of other abnormalities. This review presents current evidence on the relationship between hyperuricemia and hypertension.

Blood pressure variability provokes vascular β-adrenoceptor desensitization in rats

Spontaneous variation in blood pressure is defined as 'blood pressure variability' (BPV). Sinoaortic denervation (SAD) is characterized by BPV without sustained hypertension. In the present study, we investigated whether BPV could be related to vascular β-adrenoceptor desensitization in rats. Three days after surgery (SAD and control), aortic rings were placed in an organ chamber and the relaxation stimulated by β-adrenoceptor agonists, isoprenaline, terbutaline, BRL37344 and cyanopindolol was verified. The participation of intracellular nucleotides signaling pathways was also verified using forskolin, sodium nitroprusside and acetylcholine to induce relaxation. The effects of BPV on the increase in endothelial cytosolic Ca(2+) concentration stimulated by the β2-adrenoceptor agonist was examined by confocal microscopy. In addition, the vascular expression of the β2-adrenoceptor was also examined by immunohistochemistry. The results show that isoprenaline and terbutaline-induced relaxation was lower in the aortas of rats with BPV. Relaxation responses to other vasorelaxant compounds were similar in both groups of rats. Histological analysis revealed a lower level of β2-adrenoceptor and confocal microscopy showed minor cytosolic Ca(2+) concentration in endothelial cells stimulated by the β2-adrenoceptor agonist in rats with BPV. In conclusion, BPV leads to desensitization of the β2-adrenoceptor, which could contribute to worse β-adrenoceptor agonist-induced relaxation in isolated aortas.

Administration time-dependent effects of combination therapy on ambulatory blood pressure in hypertensive subjects

The aim of this study was to explore the influence of combination therapy in different administration time on antihypertensive efficacy and blood pressure variability in patients with essential hypertension. A total of 86 patients with stage II to III essential hypertension were randomly divided into 4 groups: taking indapamide and losartan potassium together in the morning or in the evening 2 to 4 hours before sleep, indapamide in the morning and losartan potassium in the evening, losartan potassium in the morning and indapamide in the evening. Ambulatory blood pressure monitoring was performed before and 12 weeks after the medication. The result showed that statistically significant reductions from baseline of systolic blood pressure/diastolic blood pressure occurred in all treatment groups. There was no significant difference of the reductions or SI among the four groups, neither the rate of decline of BP in the night or the circadian rhythm. In group B, the numbers of rapid rise in BP in the morning hours were significantly less after the medication, while not in the other groups. It is concluded that independent of the administration time, both once-daily treatment and component-based dual therapy had significant antihypertensive effect, but the night taken-together combination resulted in reductions of BP, SI and morning blood pressure peak that may have advantages over the other combinations, without the increased incidence of hypotension at night. Medicines should be taken 2 to 4 hours before sleep.